Climbing apparatus and method

ABSTRACT

An apparatus is disclosed for climbing objects such as trees, poles, pipes, and the like. The apparatus includes at least one actuator with at least two clamps operatively attached to the actuator. Each of the clamps has an opening, which is at least as large as the cross-sectional measurement of the object being climbed. Links are attached to the clamps. A controller directs operation of the climbing apparatus.

[0001] This work was funded in part by the Defense Advanced ResearchProjects Agency (DARPA), Contract #MDA972-98-c-0009. The U.S. Governmentmay have certain rights in this invention.

INCORPORATION BY REFERENCE

[0002] The following U.S. patents are fully incorporated herein byreference: U.S. Pat. No. 4,793,439 to Crawford (“Apparatus for ClimbingTrees, Poles and the Like and Being Remotely Controlled from GroundElevation”); U.S. Pat. No. 5,301,459 to Eliachar et al. (“Tree ClimbingDevice”); and U.S. Pat. No. 5,799,752 to Perry (“Climbing Device”).

BACKGROUND OF THE INVENTION

[0003] This invention relates generally to a climbing device and thelike and specifically to a device for climbing poles, trees, and othertall structures, as well as pipes and irregular structures.

[0004] The technology available for power line/telephone maintenance,tree surgery, pipe maintenance, repair of high-masted poles (such aslight poles) has utilized various approaches in accessing elevatedlocations to perform specific tasks. For example, devices such as poleand tree ladders provide support to a user as they climb a tree or pole.One such device is disclosed in U.S. Pat. No. 5,799,752 to Perry. InPerry, a clamp engages three sides of a tree trunk, gripping the treebetween opposed arms of the clamp to which is attached a ladder. Apartfrom using ladders, trees or poles are scaled through the use of handlines and/or climbing spurs. Lifting devices, which a person is raisedto various heights, have also been employed, but these devices areexpensive and slow-moving.

[0005] U.S. Pat. No. 5,301,459 to Eliachar et al. provides an alternateapproach for climbing trees having straight trunks and no branches. Thedevice of Eliachar, which is directed to the maintenance of palm trees,employs two pairs of arms, which are capable of opening and closingaround a tree trunk and of climbing the tree trunk through theactivation of hydraulic cylinders. Operation of the climbing unit isdirected by a programmable controller. A remotely-controlled device forpositioning equipment at working elevations is taught in U.S. Pat. No.4,793,439 to Crawford. The apparatus of Crawford employs a frame havingoperating arms which at least partially encircle the tree or pole andsecure the frame to the tree. A hydraulically driven telescoping mastalso is equipped with gripping arms, which are hydraulically actuatedindependently of the gripping arms of the main frame. The gripping armsof the main frame and the hydraulically driven telescoping mast aresequentially activated to cause the apparatus to climb a tree or pole.The gripping arms fully retract to permit the apparatus to pass betweenlimbs. A winch and cable system controlled by operating personnelprovides for lifting objects, such as tools, to the working level or forlowering objects, such as cut branches, to the ground.

[0006] However, there are numerous disadvantages to existing approachesfor scaling tall structures for repair or maintenance. There is asignificant possibility that when using climbing spurs, ladders, etc.,personnel may fall. Hand lines may slip or break, or a limb could break,possibly falling on personnel or damaging objects at the surface. Someapproaches, such as cranes, are costly, their operation is slow, andthey require sufficient ground clearance for maneuvering the cab and forvertical movement of the lifting arm and cradle. Existing remotelycontrolled devices have been narrowly directed to the movement of toolsto a work location or to the maintenance of specific types of trees. Itis desirable to provide an apparatus that is capable of safely andefficiently climbing trees, poles, posts, pipes, etc. while being underthe control of personnel at ground level, and, when in position,performing varied maintenance and/or repair tasks.

SUMMARY OF THE INVENTION

[0007] Briefly stated, and in accordance with one aspect of the presentinvention, there is disclosed an apparatus for climbing objects such astrees, poles, pipes, and the like. The apparatus includes at least oneactuator with at least two clamps operatively attached to the actuator.Each of the clamps has an opening, which is at least as large as thecross-sectional measurement of the object being climbed. Links areattached to the clamps. A controller directs operation of the climbingapparatus.

[0008] In accordance with another aspect of the invention, there isdisclosed a method for operating a climbing device, which has at leastone actuator, at least two clamps operatively connected to at least twolinks, and a controller. The method includes engaging a structure to beclimbed in at least two locations with the clamps. One of the clamps isbrought into a perpendicular position relative to the structure and thendisengaged from the structure. The disengaged clamp is then moved to asecond position along the structure that is closer to an engaged clamp,at which point the disengaged clamp re-engages the structure. Adifferent clamp is then brought into perpendicular relationship with thestructure and then disengaged from the structure. This clamp is thenmoved to a position more distant from the other now engaged clamp andre-engages the structure. This sequence of motions is repeated until adesired location is reached on the structure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The foregoing and other features of the instant invention will beapparent and easily understood from a further reading of thespecification, claims and by reference to the accompanying drawings inwhich:

[0010]FIG. 1 illustrates the clamping mechanism of the subject inventionin its unclamped position;

[0011]FIG. 2 illustrates the clamping mechanism of the subject inventionin its clamped position;

[0012]FIG. 3 illustrates the operational steps for the apparatus of thesubject invention;

[0013]FIG. 4 illustrates the engaged and unengaged positions for theclamping mechanism according to the subject invention;

[0014]FIG. 5 illustrates the operation of the apparatus of the subjectinvention as it moves around obstacles in its path; and

[0015]FIG. 6 illustrates alternate embodiments for the clamp portion ofthe subject invention.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The climbing apparatus and method disclosed herein provide thecapability for accessing elevated sites, which a human cannot reachwithout difficulty or without encountering safety risks. Such sitesinclude, but are not limited to, structures that will not support theweight of a person, areas that may be obstructed (for example, deep intoa tree or a bridge), or locations close to high voltage lines. Severalcharacteristics are necessary in a device to access these sites, such asthe ability of the device to grip and release the structure it isclimbing as well as the ability to move at least bi-directionally alongthe structure being scaled. FIG. 1 provides a simplified diagram of oneembodiment of the clamping mechanism disclosed herein and its manner ofengaging the structure. In the side view in this figure, structure 110is engaged by clamping mechanism 120 to which load 130 is attached. Thetop view shows clamp 120, which may generally take the form of a “C” inits engaged but unclamped position around structure 110.

[0017] As will be appreciated by those skilled in the art, clamp 120 maytake other forms, as illustrated in FIG. 6. Forms generally angular orrectilinear in shape or those combining curvilinear and rectilinearfeatures would also provide sufficient engagement with the structurebeing climbed, all of which are contemplated by this disclosure and thescope of the claims herein. The preferred size for the open end of theclamp would be any size larger than the diameter or cross-section of thestructure being climbed. Of course, if the clamp opening issubstantially larger than the diameter of the structure, the angle atwhich the clamp effectively grabs the pole increases. The climbingapparatus may either assume that it is properly engaged, in thoseconfigurations operating open loop without sensing, or contact, touch,or force sensors may be incorporated into the climbing apparatus toensure proper engagement. If improper engagement is sensed, controlsoftware reacts to this and applies appropriate measures such asre-attempting engagement or attempting engagement at a differentlocation.

[0018] Referring now to FIG. 2, the operational position of the clamp isillustrated. In the side view of the operational position, clamp 220engages structure 210, with clamp 220 supporting load 230. In the topview, clamp 220 is seen gripping structure 210, which results when clamp220 is inclined such that the angular cross-section of the engagedportion of structure 210 interferes with the internal diameter of clamp220.

[0019] Turning now to FIG. 3, the sequence of operations enabling theclimbing mechanism to move along a structure is illustrated. At thefirst step, clamps 320 and 340 are in engaged positions on structure310, with linkages 330 connecting clamps 320 and 340. Example materialsfrom which the clamps and linkages may be fabricated include metals,woods, plastics, or other rigid or semi-rigid materials.

[0020] Initially clamp 340 releases as it reaches a positionperpendicular to structure 310 while clamp 320 remains clamped tostructure 310 and linkages 330 are in an extended configuration tomaximize the distance between the connected ends of clamps 320 and 340.At step two, linkages 330 move to an angular position relative to eachother, thus reducing the distance between clamps 320 and 340 by movingclamp 340 closer to clamp 320. Clamp 340 remains in its released orunclamped position while clamp 320 remains in its clamped position. Atstep three, clamp 340, which has moved to a new location on structure310, becomes clamped to structure 310. Clamp 320 remains in its originalclamped position and linkages 330 remain in angular relationship to eachother. At step four, clamp 320 releases the structure by moving to anapproximately perpendicular position relative to structure 310. Clamp340 remains in its clamped position and linkages 330 retain theirangular relationship to each other.

[0021] At step 5, linkages 330 have moved to a fully extended position,which maximizes the distance between the attached ends of clamps 320 and340. Clamp 340 remains in its clamped position and clamp 320, in itsunclamped configuration, moves along structure 310. Finally, at step 6clamp 320 clamps to structure 310 at its new position. Clamp 340 remainsclamped to structure 310 and linkages 330 remain in a fully extendedconfiguration. At this point the sequence of steps may be repeated tocontinue movement of the climbing mechanism along the structure.Although only two links are illustrated in the figures herein, it willreadily be appreciated that in an alternate embodiment more than twolinks could be beneficially employed to move the apparatus along asurface. The motor causing the movement of the links is included withinthe structure of the links. A controller (not shown) may be eitherincluded in the structure, attached separately to the structure, orincluded in a remote control module.

[0022] In addition to moving along a structure, an alternate embodimentof the apparatus described herein is capable of moving around obstacleson a structure by engaging and disengaging the structure as needed.Referring to FIG. 4, there is shown clamp 420 in both clamped andunclamped configurations around structure 410. In both cases clamp 420is connected to a linkage at attachment point 450, which also holds theactuator which enables movement of clamp 420 in a plane perpendicular tothe structure.

[0023]FIG. 5 illustrates another possible configuration for thisembodiment as the climbing apparatus moves along a structure. Hereclimbing apparatus 500 includes at least three clamps 520, 540, and 560connected by linkages 530. In this embodiment the clamp encounteringobstacle 570 on structure 510 disengages from structure 510 while theremaining clamps continue moving along the structure. Examples ofobstacles 570 include branches and attachments to the structure.Although three clamps connected with two linkages between each clamp areillustrated, it will be appreciated that a plurality of clamps andlinkages may be utilized in the climbing apparatus and suchconfigurations are fully contemplated by this specification and thescope of the claims herein. In FIG. 5 clamp 520 has already encounteredobstruction 570, disengaged from structure 510 as clamps 560 and 540continued to move apparatus 500 along structure 510, and then re-engagedwith structure 510. Apparatus 500 then continued moving along structure510 until clamp 560 encountered the obstacle. As illustrated in FIG. 5,clamp 560 then disengages from structure 510 to clear the obstacle whileclamp 520 remains in its clamped position and clamp 540 has moved to aperpendicular relationship with structure 510 preparatory to movingalong the structure. Complete disengagement with the structure isaccomplished without sensors through translation of the clamp through aspecified range of movement. For those embodiments in which sensors areincluded, sensors measure either the change of forces internal to thestructure, or touch, force, or contact sensors detect disengagement.

[0024] As described above, linkages 530 move from angular to fullyextended positions to enable movement of apparatus 500 along thestructure. When the climbing apparatus 500 has moved sufficiently forclamp 560 to clear obstruction 570, clamp 560 swings back intoengagement with structure 510. When clamp 520 encounters the obstacle,it disengages and swings away from structure 510 as clamps 560 and 540continue to climb. When clamp 560 encounters the obstacle, clamps 520and 540 remain engaged and continue climbing while clamp 560 isdisengaged. When clamp 540 encounters obstacle 570, clamps 520 and 560continue climbing as clamp 540 disengages from structure 510. Thisengagement and disengagement sequence of movements enables the apparatusto transition from climbing to translation along a horizontal bar or ahorizontal cable.

[0025] For those embodiments in which the apparatus is remotelycontrolled, an operator directs the movement of the apparatus to clearan obstacle. For those embodiments in which the apparatus operatesautonomously, touch, force, or contact sensors sense contact with theobstacle. The on-board controller then causes the colliding arm to moveout of the way of the obstacle. The on-board controller may then eithercontinuously attempt re-engagement as the rest of the system climbs (forexample, repeatedly touching and sensing the obstacle until the obstacleis cleared), or it may sense the obstacle without contact, throughproximity sensing.

[0026] While the present invention has been illustrated and describedwith reference to specific embodiments, further modification andimprovements will occur to those skilled in the art. For example, theapparatus is also able to move along structures that are semi-flexibleor not precisely straight, such as piping, which includes bends orcurved structural supports. It is to be understood, therefore, that thisinvention is not limited to the particular forms illustrated and that itis intended in the appended claims to embrace all alternatives,modifications, and variations which do not depart from the spirit andscope of this invention.

What is claimed:
 1. An apparatus for climbing objects such as trees,poles, pipes and the like, comprising: not less than one actuator; notless than two clamps operatively attached to said actuator, said notless than two clamps having an opening not less than the cross-sectionalmeasurement of the object to be engaged; not less than two linksoperatively attached to said not less than two clamps; and a controller.2. The apparatus for climbing objects according to claim 1, wherein saidnot less than two clamps are C-shaped.
 3. The apparatus for climbingobjects according to claim 1, wherein said not less than two clamps arecurvilinear in shape.
 4. The apparatus for climbing objects according toclaim 1, wherein said not less than two clamps are rectilinear in shape.5. The apparatus for climbing objects according to claim 1, wherein saidnot less than two clamps are characterized by both rectilinear andcurvilinear features.
 6. The apparatus for climbing objects according toclaim 1, further comprising at least one sensor for sensing engagement,disengagement, or obstacles.
 7. The apparatus for climbing objectsaccording to claim 6, wherein said not less than one sensor comprisestouch sensors.
 8. The apparatus for climbing objects according to claim6, wherein said not less than one sensor comprises force sensors.
 9. Theapparatus for climbing objects according to claim 6, wherein said notless than one sensor comprises contact sensors.
 10. The apparatus forclimbing objects according to claim 1, wherein said controller comprisesan on-board controller.
 11. The apparatus for climbing objects accordingto claim 1, wherein said controller comprises a remote controllingdevice.
 12. The apparatus for climbing objects according to claim 1,wherein said not less than two clamps comprises two clamps.
 13. Theapparatus for climbing objects according to claim 1, wherein said notless than two links comprises two links.
 14. The apparatus for climbingobjects according to claim 1, wherein said not less than one actuatorcomprises one actuator.
 15. The apparatus for climbing objects accordingto claim 1, further comprising software directing movement of theclimbing apparatus.
 16. A method for operating a climbing device, saidclimbing device including not less than one actuator, not less than twoclamps operatively connected to not less than two links, and acontroller, the method comprising: engaging a structure to be climbed innot less than two locations with said clamps; bringing a first clampinto perpendicular relationship with said structure at a first position;disengaging said first clamp from said structure; moving said firstclamp to a second position along said structure that is closer to asecond clamp engaged with said structure; re-engaging said structure atsaid second position with said first clamp; bringing said second clampinto perpendicular relationship with said structure at a third position;disengaging said second clamp from said structure; moving said secondclamp to a fourth position along said structure that is more removedfrom the position of said first clamp; re-engaging said structure atsaid fourth position with said second clamp; repeating the sequence ofbringing a clamp into perpendicular relationship with said structure,disengaging a clamp, moving the disengaged clamp to a new position andre-engaging the structure with the clamp until the desired location isreached on said structure.
 17. The method for operating a climbingdevice according to claim 16, wherein moving said first clamp to asecond position along said structure that is closer to a second clampfurther comprises bringing the links to an angular position relative toeach other.
 18. The method for operating a climbing device according toclaim 16, wherein moving said second clamp to a fourth position alongsaid structure that is more removed from the position of said firstclamp further comprises bringing the links to an extended positionrelative to each other.
 19. The method for operating a climbing deviceaccording to claim 16, wherein the controller directs the movement ofthe clamps and links.